Electro-static discharge (ESD) is a major reliability issue in printed circuit boards and/or integrated circuits (ICs). ESD is a transient surge in voltage (negative or positive) that may induce a large current in. The large circuit current in a circuit damages the elements, conductive paths, and other parts of the IC's circuits and causes a failure during testing on some disk drives. To protect circuits against damage from ESD surges, various protection schemes attempt to provide a discharge path for both positive and negative ESD surges.
An example of an ESD surge problem is meeting system-level ESD testing requirements on some disk drives using a hard disk drive (HDD) controller. Many experiments have been performed to understand the underlying root cause mechanism of the ESD discharge disrupting the operation of the disk drive controller. Interaction between the disk drive controller and a double data rate synchronous dynamic random-access memory (DDR SDRAM) may be corrupted by the ESD surge. If isolating the PCB assembly from the case and providing capacitive or resistive coupling to spread the discharge current flowing through the PCB assembly over time, a decrease in sensitivity to the ESD event may be provided, however, the sensitivity may not be decreased enough to meet the goals, and at high enough ESD voltages arcing from the mounting screws to nearby PCB assembly ground points may be observed.